Brettanomyces and Sour Beers

Slides from a talk about brettanomyces and sour beers given by Jacques Marais at the April 2018 LAB meeting.

Transcript

1. BRETTANOMYCES AND SOUR BEERS JACQUES MARAIS
2. BRETT AND SOUR BEERS Brettanonomyces • Background • Yeast profile • Brett character • BJCP styles • Commercial examples • Brett metabolism • Brett strains • Brett off flavours Brewing with brett • Process • Tips Sour Beers • BJCP and styles • Characteristics • Lactobacillus • Pediococcus • Commercial bugs Brewing Sour beers • Commercial bugs • Recipe • Process and tips • Fermentation • Pellicle • Fruit & wood Lambic • Background • BJCP Style • Characteristics Brewing a Lambic • Turbid Mash • Boiling and hops • Fermentation • Bottling • Blending
3. WHAT IS BRETTANOMYCES? ➢ BRETTANOMYCES (KNOWN AS “BRETT”) IS A YEAST. OVER 1000 IDENTIFIED SUB-SPECIES. ➢ DISCOVERED BY NIELS CLAUSSEN FROM CARLSBERG BREWERY IN 1903 AFTER ANALYSING BRITISH PORTERS. ➢ “BRETTANOMYCES” IS LATIN FOR “BRITISH FUNGI” ➢ CALLED A “WILD YEAST” YET MORE COMMON IN CRAFT BEERS
4. BRETTANOMYCES PROFILE ➢ Attenuation: high to very high 80-99%. ➢ Alcohol tolerance +/- 10-12% ➢ Starts and ferments slow: ➢ Primary 3 day lag ➢ Usually 2-3 months to finish ➢ Flocculation: low (high over time) ➢ Fermentation temperature ➢ 18-40 deg celcius: best at 25-33 deg celcius ➢ Metabolic compounds unaffected by temperature ➢ Higher temperature faster fermentation ➢ Aerobic – prefers oxygen ➢ No autolysis, no oxidisation, no fusel alcohols ➢ No glycerol - thin body ➢ Fermentation ➢ Ferments many compounds Sacch cannot ➢ Creates ascetic acid from oxygen ➢ Fruity esters ➢ Funky phenols ➢ Few cells keep fermenting ➢ Infection of Brett ruins a normal beer ➢ Changes a lot over time ➢ Cleans up after Bacteria ➢ Other ➢ Multiple krausens as it swaps sugars ➢ Could create a pellicle after 1-2 months
5. BRETT CHARACTERISTICS ➢ Brettanomyces responsible for “funky, barnhouse, horse blanket” aromas and flavours common in lambics, geuezes etc: ➢ Produces 4-ethyl phenol and 4-vinyl phenols ➢ 4-vinyl phenols converted to 4-ethyl over time ➢ Produces a lot of esters: ➢ Ethyl acetate, caprylate, caproate ➢ Fruity and musty aromas ➢ Produces acetic acid (vinegar) in the presence of oxygen ➢ Brett off flavours ➢ Ascetic – too much oxygen ➢ Plastic – fermentation temperature too high ➢ Burylic acid – goat/cheese ➢ Too thin – add adjuncts ➢ Too much funkiness
6. BEER STYLES ➢ American wild ale (BJCP 28) ➢ Brett beer (BJCP 28A) ➢ Mixed fermentation sour beer (BJCP 28B) ➢ Wild specialty beer (BJCP 28C) ➢ Others ➢ Brett with any other beer (specialty section) ➢ Fruit beer (BJCP 29A-C) could contain brett ➢ Commercial examples ➢ Orval – brett B in secondary ➢ Crooked stave – 100% brett beers ➢ Typical examples ➢ Brett IPA – drink young! ➢ Brett saison ➢ Old ales ➢ Historical british porters
7. BRETT METABOLISM Produced by Brett Requires Characteristics Comments 4-ethyl guaiacol 4-vinyl guaiacol Smoky, spicy, barnyard aromas More common in Brett beers in secondary, varies by strain. Phenols: 4-ethyl, 4-vinyl 4-vinyl phenols and Fatty acids Funky, horse-blanket, musty flavours/aromas Unique to Brett Acetic acid Oxygen, ethanol Vinegar, tartness Also produced by Acetobacter Ethyl acetate Ethanol + acetic acid Fruity, pear, solvent High flavour threshold Ethyl caprylate Caproic/caprylic acid Waxy, pineapple, musty Not found in other beers Ethyl caproate Caproic/caprylic acid Sweet, fruity Not found in other beers Diacetyl α-acetolactate Buttery aroma Brett cleans up diacetyl Fermented by Brett Source Characteristics Comments Dextrin High mash, Crystal Provides head and body Some still remains Oxygen Oxidised wort Cardboard, sherry etc. Removes oxidisation, adds tartness Lactose Addition Sweet Brett L cannot ferment Some Infections Pedio off flavours Mold, sicky flavours Cleans up after Pedio
8. TYPICAL BRETT TYPES Type of Brett Examples Characteristics Origin Brettanomyces Lambicus (Brett L) WL653 WY5526 Most Funky of Brett strains. Horse blanket, barnyard etc. Ferments quickly Various Lambic breweries. Most likely Cantillon Brettanomyces Bruxelles (Brett B) WL650 WY5112 Medium intensity and ferments very slowly. Good funkiness with anaerobic fermentation, hence secondary or bottling From Orval Brettanomyces Claussenii (Brett C) WLP645 Low funkiness, but more fruit. No large taste contribution. Original from English porters Brettanomyces Trois Vrai WLP648 Complex sour character with pear aroma. Good for primary fermentation. Unknown. Vrai means “true” in French. • Many classification errors • Many subspecies with different characteristics
9. BREWING WITH BRETT Process 100% Brett Secondary or bottle Tips Starter 1 week per growth phase Lager level cell count No starter required Low cell count 5-20 billion cells per 20l Oxygen good for growth, but creates ascetic acid Mashing Mash low Mash high Basic sugars ferment faster Aeration Low High for primary, none thereafter Recipe >10% unmalted adjuncts for body Low attenuating primary yeast for maximum funk Hops More hops than usual Interesting esters from hop oils Brett eats hop oils Brett type Brett 3 is fruity Brett L is funkiest Brett C for less Brett character Fermentation Ferment at >25 deg 1 month is enough Leave for 2-3 months Purge with CO2 Bottling Slow to carbonate Stable FG Once pellicle dropped Never bottle FG > 1.006 Age Fruity when young. Clean Funkier and more complex Taste changes of time
10. BREWING WITH BRETT Vessel ➢ Plastic: too porous ➢ Glass/metal is better ➢ Fermentation ➢ Keep fairly warm ➢ Longer storage: No Autolysis, No Problem ➢ Sanitisation ➢ Separate fermenter, syphons, bottling equipment ➢ Starsan ➢ ineffective Dies at > ➢ 70-80 ͦ C, or Caustic soda Brett storage ➢ In the fridge for < ➢ 3 months - starter In wort at room temp ➢ – top up 3-6 months ➢ Mashing ➢ Ferulic acid rest: Fruity aromas ➢ Protein rest helps spice, smoke ➢ Shorter mash for more body ➢ Acidulating wort ➢ Acid malt, kettle sour, lactic acid ➢ Helps Brett attenuate ➢ Reports of fruitier beers ➢ 4.5-4.8 pH Pre pitching ➢ Additions ➢ Wood: Create complex flavours ➢ Spices: Brett metabolises many spices ➢ Fruit: Works well
11. SOUR BEER STYLES ➢ Flanders Red (BJCP 23B) & Oud Bruin (23C) ➢ Sour beers with distinct sour cherry and wood ➢Lambic (23D) ➢ Belgian sour beer using natural fermentation ➢ Fruit lambic (23F) ➢ Gueuze (BJCP 23E) ➢ Blend of differently aged lambics ➢ Lactobacillus only ➢ Berliner weisse (23A) ➢ Gose & Lichtenhainer
12. SOUR BEER CHARACTERISTICS ➢ Flavours ➢ Sour!!! ➢ Malt: Low to very high ➢ Fruit and Funk! ➢ Very Complex ➢ Resin/Tannins are allowed ➢ Acids ➢ Lactic Acid: Clean sour flavour ➢ Ascetic acid: Vinegar, mouth coating ➢ Off Flavours ➢ Vinegar: Too much Ascetic acid ➢ Plastic: Ethyl acetate ➢ Phenolic/Band-aid: ➢ Goat: Caprylic acid, ranc ➢ Cheesy: Burylic acid ➢ Aromas ➢ Fruitiness: Apple, citrus, grapes etc. ➢ Funky: Brett character ➢ Spicy phenolics ➢ Smells “Sour” ➢ Head Retention: Usually low ➢ Lactobacillus breaks down proteins (>5.0 pH) ➢ Carbonation: ➢ Lambic: None – 1.5 vol CO2 ➢ Geueze: 3.0-3.5 vol CO2 ➢ Body & Mouthfeel ➢ Dry, but adjuncts help the body ➢ Thin beer not desriable
13. SOUR BEER BUGS Lactobacillus (aka. ➢ Lacto) Creates Lactic acid (fast!) ➢ Ferments best at ➢ 38-49 ᵒC Good for fast souring: ➢ 2-5 days! Does not require oxygen ➢ Drops pH down to ➢ 3.3 Cell growth is very fast ➢ Hop intolerant (> ➢ 8 IBUs) Alcohol tolerance: Varies, ~ ➢ 7% Homo/Heterofermentative: ➢ Homo: Only lactic acid ➢ Hetero: Other by ➢ -products incl. alcohol Responsible for Berliner ➢ Weisses Sour Mash: Uses ➢ Lacto within the malt to pre- sour the wort ➢ Pediococcus Damnossus (aka. Pedio) ➢ Creates Lactic acid (slow!) and other acids ➢ Ferments at 13-35 ᵒC (best at 20-25 ᵒC) ➢ Very slow to start: 1-3 months ➢ Drops sourness down to <3.0 pH ➢ Hop tolerant ➢ Requires low levels of oxygen ➢ Consumes various sugars/dextrins etc. ➢ Responsible for “Ropiness” (Brett cleans up!) ➢ Creates Diacetyl (Brett cleans up!) ➢ Used in wine making: ➢ Chardonnays ➢ Malolactic fermentation
14. SOUR BEER ROPINESS
15. COMMERCIAL BUGS Bacteria Example Characteristics Lactobacillus Brevis WLP672 More lactic acid Lactobacillus Delbruekii WLP677 Less sour. Common in Berliner weisse Pediococcus Damnosus WLP661 Many complex acids Acetobacter none Creates acetic acid (vinegar) Pre-packed Blends Example Characteristics Lambic Blend WLP655 Good for a Lambics base. Also contains Sacch strain Yeast Bay Sour Blend Melange Sours very fast Farmhouse Blend WLP670 American sourced. Complex, not that sour. Berliner weisse Blend WLP630 The name says it Wyeast Roeselare Blend WY3763 Rodenbach blend Flemish ale WLP665 Flanders Red, Oud Bruin. Cherry sourness
16. BREWING SOUR BEERS ➢ Water Treatment ➢ Lambics: Hard, Low sulphates ➢ Magnesium: Accentuates perception of sourness (~50ppm) ➢ Ingredients ➢ Anything to add body! ➢ Mashing: ➢ Mash high: ➢ Turbid Mash: Used in Lambics ➢ Sour Mash: Berliner Weisse ➢ Hops ➢ 0 to 10 IBU ➢ Fermentation ➢ Mixture of Brett, Lacto, Pedio ➢ Many methods: Understand your bugs
17. MIXED CULTURE FERMENTATION Vessel ➢ Plastic: Too porous, ➢ cannot see inside Glass: Difficult to ➢ clean, easy to see Metal: Easy to clean, ➢ cannot see inside Keep out of light ➢ ➢ Samples ➢ Introduces oxygen ➢ Not always representative of final beer ➢ Not sour enough: ➢ Add food: Maltodextrin ➢ Too sour: Blend?, add CaCO3 ➢ Fermentation ➢ Starters: ➢ Brett: Takes 1 week per cycle ➢ Blends: Lacto dominates ➢ SLOW: Takes > 6 months ➢ Pitching the bugs: ➢ With Sacch or Secondary ➢ Most blends lack cell count ➢ Dregs from bottled beer help ➢ Temperature ➢ Hotter means faster ➢ More complexity when cooler ➢ Bottling ➢ OG stable and below 1.007 ➢ Takes ~1 month to carbonate
18. WHAT IS A PELLICLE? ➢ Appears after 1-3 months ➢ May appear bubbly, web-like ➢ Usually white, varies in colour ➢ Only in the presence of oxygen ➢ Biofilm: community of microorganisms connected using an extracellular matrix ➢ Bubbles mean action! ➢ Function: ➢ Enables oxidative metabolism i.e. Access to oxygen ➢ Believed to “protect” the beer from oxygen ➢ Formed by ➢ Brett is most common ➢ Pedio, Lacto and others ➢ What to do? ➢ Nothing ➢Take a Selfie! ➢ Infected: make a sour beer! ➢ Do not disturb or break the pellicle ➢ Bottle when pellicle drops?
19. FRUIT AND WOOD ➢ Fruit ➢ Common in Belgian Sour beers: Kriek, Frambois etc. ➢ Whole fruit, puree, fruit concentrate etc. ➢ Use lots! Typically 2-6kg per 20ltrs, but varies per fruit ➢ Added sugar creates a second fermentation and adds alcohol ➢ Time: 2-4 months ➢ Adds complexity and may sour the beer further ➢ Sanitisation: Freezing, vodka, None! ➢ Wood ➢ Wood chips, cubes, barrel ageing ➢ Chips: 20-40g for 1 month gives a slight wood character ➢ Wood from previous casks adds complexity ➢ Sanitisation: boil, soak in alcohol ➢ Can be reused for later projects
20. LAMBIC & GEUEZE ➢ Lambic ➢ Spontaneously fermented wheat beer originated in Belgium ➢ Brewing process unique ➢ Only one regular commercial bottling ➢ Geueze ➢ Blend of various aged Lambics ➢ Geuzestekerij: Blender, not a brewery ➢ Faro ➢ Lower alcohol Lambic, with added sugar (pasteurised) ➢ HORAL ➢ High Council of Artisanal Lambic Beers ➢ EU protection of Lambic, Geueze and Kriek ➢ “Oude/Vieille” Only 100% spontaneously fermented beers ➢ Members: 8 Breweries (not Cantillon!)
21. BJCP 23d Lambic A fairly sour, often moderately funky wild Belgian wheat beer with sourness taking the place of hop bitterness in the balance. Traditionally spontaneously fermented in the Brussels area and served uncarbonated, the refreshing acidity makes for a very pleasant café drink Aroma: Sour, Fruity, Funky, Complex. More funk and complexity with age Appearance: Light hazy to clear. No head retention Flavour: Sour, Apples, Citrus, Funk. Young: Sour and fruity. Older: More complexity. No hops Mouthfeel: Drier with age. Sourness and flavour replace body. Tart/Puckering/Tannins in younger versions Results vary a lot! LAMBIC CHARACTERISTICS
22. LAMBIC RECIPE AND PROCESS • Recipe • Typically 20-40% Flaked wheat, then Pilsen • OG: 1.040 – 1.052, FG: 1.001-1.010 • IBU: 0-10 • Uses aged hops: Typically 3-7 years • Process • Turbid mash • 4-6 hour boil • Wort left overnight in a Coolship during winter • Fermented in Barrels for 1-4 years • Brett and Bugs mostly in the barrels
23. BREWING LAMBIC AT HOME Turbid Mash Similar to decoction Allows for gelatinisation of starch – Food source for a long complex fermentation Tannins are desirable How: - Mash in at 45-50 degrees for 20 minutes (06-1.0 l/kg) - Remove ~15% of water in separate pot, raise to 85 degrees - Add boiling water to mash to get to 58-63 degrees, rest for 30 minutes - Remove ~20-30% of water and add to the turbid liquor, raise to 85 degrees - Add boiling water: Sacch rest at 69-72 degrees for 30-60 minutes - Mash out at 75 degrees for 10 minutes - Sparge with tubid liquor and water at 85-90 degrees Wort is murky with aromas of spice and dough Lambic brewers over sparge and boil longer for more caramel complexity
24. BREWING LAMBIC AT HOME Aged hops • Low Alpha acids allows bugs to sour the beer • Inhibits other unwanted bacteria • If none available: Low AA hops at 0-3 IBU Fermentation • Acidify the wort: helps Brett and head retention) • Typically add bugs with Sacch or in Secondary • Avoid oxygen: Purge with CO2 • Lambic barrels are not very porous • Commercial blends: Use 2-4 sachets • Add dregs from bottles over time • Leave at ~20-25 degrees for 1-4 years • Add Maltodextrin after 3-6 months • Wild fermentation: Random and mixed results Bottling • Stable FG / stable pellicle • Keg and bottle ageing Blending • Different aged Lambics: Geueze! • Blend with clean beer (Pasteurise?) • Top-up with fresh wort (faster souring)
25. BREWING LAMBIC AT HOME Lambic Recipe • Grains: 60% Pilsen, 40% Flaked wheat • Mash: Turbid mash • Pre-boil Gravity: 1.030 • Boil: 4-5 hours • Post-boil Gravity: 1.048 • Hops: 1 IBU Hallertua leaf hops 4 hours • Yeast: • Primary: Safale SO4 (1 week) • Yeast bay Melange (2 viles, no starter): 1 year • Dregs from 3-Fonteienen Geueze, Oud-Beersel over time • 20g oak chips after primary • Fermention: 20 deg throughout • Carbonation: 2.0-2.5 vol CO2